Checking and adjusting the pressure in the hydraulic brake system (Audi 100 C3)

The pressure regulator must be checked and adjusted with the vehicle parked on its wheels, unloaded, but with the fuel tank fully filled. An assistant must take the driver's seat.



"Squeeze" the rear suspension several times.

Connect the test pressure gauges in the same way as for checking the tightness of the pressure regulator.

Bleed air from both gauge hoses.

Press the brake pedal several times until the pressure gauge connected to the front wheel brake mechanism shows a pressure of 50 kg/cm². At the same time, the readings of the pressure gauge connected to the rear wheel brake mechanism should be within 32.5-42.5 kg/cm².

Press the brake pedal several times until the pressure gauge connected to the front wheel brake mechanism shows a pressure of 100 kg/cm². At the same time, the readings of the pressure gauge connected to the rear wheel brake mechanism should be within 50.0-71.5 kg/cm².

Adjust the tension of the pressure regulator spring depending on the measurement results: if the pressure in the rear wheel brake mechanism is increased, loosen the spring, and vice versa.



If the measured rear brake pressure is not within the specified limits, replace the pressure regulator.

Disconnect the control pressure gauges and bleed the air from the brake hydraulic system.